There are a few differences between the 05 and 07. 05 was the first year for the Duratec 2.0 engine used in both. If you'll look closely, the power steering pump reservoir is in a different position in the 05 than in the 07. One you can't see is that the 05 has a tubular exhaust manifold as compared to the 07 having a cast manifold. Both are what's called mani-cats since the first catalytic converter is built into the exhaust manifold.

The only problems are that the 05 had a larger hole in the TB so it would sometimes make the fuel/air mix too lean to start. This can be embarrassing, but causes no damage. What will happen is that you'll crank the engine, and it won't start the first time. This won't happen every time, but it will happen. Not all 05s experience this problem. What I do is crank for 1 sec, if it doesn't start, turn the key off, then crank again and it always starts immediately.

I'd get the 05 also, but remember- replacing a clutch in this car is not as inexpensive as, for example, a Chevy Cavalier. Our clutches use a dual mass flywheel that is actually 2 parts separated by a large spring. This takes out some of the harshness when the clutch engages the trans and engine, but it must be replaced when the clutch is replaced making the parts expensive for a clutch job. As you're going along you should save about $1200 somewhere just for parts. Figure about $500 for a clutch, $400 for a flywheel, $30 for flywheel bolts (very important), and $70 for a slave cylinder. Another $200 is in there for misc like brake fluid and a vacuum bleeder for bleeding the clutch down. Single mass flywheels are available to replace the DMF if you want something that might not have to be replaced every time. If anyone tells you that the DMF doesn't have to be replaced, then you should seek another mechanic. Research DMFs online, and you'll see what the truth is.